JPH05178188A - Traction controller for vehicle - Google Patents

Abstract

PURPOSE:To eliminate an effect of hydraulic pressure at the time of brake returning by differentiating switch timings of first and second switch valves between a master cylinder and an actuator, as well as between an external hydraulic pressure source and the actuator, during acceleration slip control, and by cutting the second switch valve after pressure reduction time has passed. CONSTITUTION:A first switch valve (e) is provided between a master cylinder (a) and a brake hydraulic pressure control actuator (d), while a second switch valve (f) is provided between an external hydraulic pressure source (b) and the brake hydraulic pressure control actuator (d). The time for pressure reduction of brake hydraulic pressure for a wheel cylinder (c) is calculated by a pressure reduction time calculation means (g) according to the pressure increasing time for the brake hydraulic pressure control actuator (d), during acceleration slip control, where the first switch valve (e) is on the cutting side, and the second switch valve (f) is on the connection side. The second switch valve (f) is then changed over to the cutting side, and after a fixed period of time has passed, the first switch valve (e) is changed over to the communication side. The brake hydraulic pressure control actuator (d) is returned to a normal condition by a first brake returning control means (h).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle traction control device having a brake fluid pressure control actuator which is shared during acceleration slip and deceleration slip.

[0002]

2. Description of the Related Art Conventionally, a vehicle traction control device having a brake fluid pressure control actuator which is commonly used during acceleration slip and deceleration slip is disclosed in, for example, Japanese Patent Laid-Open Publication No. Sho 5 (1998).
The device described in Japanese Patent Laid-Open No. 8-122246 is known.

[0003]

However, in the above-mentioned vehicle traction control device, in the case of performing the brake recovery from the acceleration slip control to return to the state of waiting for the normal brake operation, when the acceleration slip brake control is completed, The first switching valve is switched to the side connecting the master cylinder and the brake fluid pressure control actuator,
A sequence of switching the switching valve to the side that shuts off the external hydraulic pressure source and the brake hydraulic pressure control actuator, and returning the pressure increasing valve and pressure reducing valve of the brake hydraulic pressure control actuator that controls the brake hydraulic pressure to the wheel cylinder to the normal state. Since the return operation of is performed at the same timing, there are problems listed below.

(1) From the switching of the first switching valve to the second
When the switching response of the switching valve is delayed, both valves momentarily become the communication side, and the hydraulic pressure from the external hydraulic pressure source escapes to the master cylinder after passing through the second switching valve and the first switching valve, May be damaged.

(2) From the switching of the first switching valve to the second
When the switching response of the switching valve is quick, both valves momentarily become the shut-off side, the hydraulic pressure of the brake fluid pressure control actuator escapes to the wheel cylinder, the wheel cylinder is pressurized and the brake becomes effective, and the feeling of deceleration occurs. I have something to do. In the worst case, it will be in the rear lock state,
Stability decreases.

(3) In the case where the brake is restored while the high pressure brake fluid is being supplied to the wheel cylinders due to the pressure increase in the acceleration slip brake control, and then the acceleration slip control or the deceleration slip control is performed, The brake fluid returned to the reservoir of the brake fluid pressure control actuator during pressure reduction control exceeds the reservoir capacity limit, and the pressure reduction control time cannot be set optimally, and the valve durability is reduced.

(4) In order to solve the above problem (3),
If a predetermined decompression time is secured after the end of the acceleration slip brake control to restore the brake, and if an acceleration request stop or an abnormality or a deceleration slip control request occurs during the acceleration slip brake control, there will be a response delay.
For example, in deceleration slip brake control, an increase in braking distance and a feeling of braking delay occur.

The present invention has been made by paying attention to the above-mentioned problems, and in a vehicle traction control device having a brake fluid pressure control actuator shared during acceleration slip and deceleration slip, the acceleration slip control The first object is to eliminate the influence of hydraulic pressure on the master cylinder and the wheel cylinders when the brake is restored, and to ensure proper depressurization control thereafter when the brake is restored in the normal state.

Further, when the brake is returned from the acceleration slip control, the influence of the hydraulic pressure on the master cylinder and the wheel cylinder is eliminated, and when the acceleration request stop is generated during the acceleration slip control, a high responsiveness to the request is secured. The second task is to do so.

[0010]

In order to solve the above-mentioned first problem, in the vehicle traction control device of the present invention, when the brake is restored from the acceleration slip control, the switching timing of both switching valves is shifted and the second switching is performed. The means for switching the valve to the shut-off side is set to the time when the pressure reducing time required to reduce the brake fluid pressure of the wheel cylinder to a predetermined pressure has elapsed.

That is, as shown in the claim correspondence diagram of FIG. 1, a master cylinder a which generates a hydraulic pressure by a brake operation, an external hydraulic pressure source b provided separately from the master cylinder a, and an acceleration slip state. A first switching valve e for switching connection / disconnection between the brake hydraulic pressure control actuator d for controlling the brake hydraulic pressure to the wheel cylinder c and the master cylinder a and the brake hydraulic pressure control actuator d while sharing with the deceleration slip. And a second switching valve f for switching between disconnection and connection between the external hydraulic pressure source b and the brake hydraulic pressure control actuator d, and acceleration with the first switching valve e as a blocking side and the second switching valve f as a connecting side. During the slip control, the brake fluid pressure of the wheel cylinder c is reduced to a predetermined pressure according to the pressure increasing time of the brake fluid pressure control actuator d. And a decompression time calculating means g for calculating a decompression time required for controlling the second depressurization time, and immediately after the depressurization time elapses during the acceleration slip control, the second switching valve f is switched to the shutoff side. It is characterized in that it is provided with a first brake return control means h for switching the switching valve e to the communication side and returning the brake fluid pressure control actuator d to a normal state.

In order to solve the above second problem, in the vehicle traction control device of the present invention, when the brake is restored from the acceleration slip control, the switching timing of both switching valves is shifted and the second switching valve is switched to the shut-off side. The time was taken as a means when an acceleration request stop occurred.

That is, as shown in the claim correspondence diagram of FIG. 1, a master cylinder a which generates hydraulic pressure by a brake operation, an external hydraulic pressure source b provided separately from the master cylinder a, and an acceleration slip state A first switching valve e that switches connection / disconnection between the brake hydraulic pressure control actuator d for controlling the brake hydraulic pressure to the wheel cylinder c and the master cylinder a and the brake hydraulic pressure control actuator d while sharing with the case of deceleration slip. And a second switching valve f for switching between disconnection and connection between the external hydraulic pressure source b and the brake hydraulic pressure control actuator d, and acceleration with the first switching valve e as a blocking side and the second switching valve f as a connecting side. During the slip control, when the acceleration request stop or abnormality or the deceleration slip control request occurs, the second switching valve f is immediately switched to the shutoff side. , Characterized in that the post-valve shut-off a predetermined time, and a second brake the recovery control means i for returning the brake fluid pressure control actuator d to the normal state with switching the first switching valve e to the communication side.

[0014]

The operation of the first invention will be described.

When the brake is returned from the acceleration slip control to the normal state, the depressurization time calculation means g determines the brake fluid pressure of the wheel cylinder c in accordance with the pressure increase time of the brake fluid pressure control actuator d during the acceleration slip control. The decompression time required to reduce the pressure is calculated.
Then, in the first brake return control means h, the second switching valve f is switched to the shut-off side immediately after the decompression time by the calculation during the acceleration slip control, and a predetermined time after this valve shut-off, the first switching valve e is turned on. The brake fluid pressure control actuator d is returned to the normal state while being switched to the communication side.

The operation of the second invention will be described.

At the time of brake recovery when an acceleration request stop or the like is issued during acceleration slip control, the second brake recovery control means i immediately outputs the second acceleration brake control during acceleration slip control, or when an abnormality or a deceleration slip control request occurs. The switching valve f is switched to the shutoff side, and a predetermined time after this valve shutoff, the first switching valve e is switched to the communication side and the brake fluid pressure control actuator d is returned to the normal state.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

The configuration will be described.

FIG. 2 is an overall view of a braking / driving system control system for a rear-wheel drive vehicle to which the vehicle traction control device according to the embodiment of the present invention is applied.

In this rear-wheel drive vehicle, the throttle control for controlling the motor throttle opening so that the rear-wheel slip ratio falls within the optimum allowable range when acceleration slip occurs and the left and right rear wheels independently when acceleration slip occurs. A traction control system (equal to an acceleration slip brake control system on the brake control side) that is used together with a brake control that applies braking force is provided, and front and rear wheel brake fluid pressure control is performed to prevent wheel lock during deceleration slip. It is equipped with an anti-skid brake control system (equivalent to a deceleration slip brake control system). And
Centralized electronic control of these systems is performed by a traction control system & anti-skid brake control system electronic control unit TCS / ABS-ECU (hereinafter abbreviated as TCS / ABS-ECU).

The TCS / ABS-ECU includes a right front wheel speed sensor 1
Right front wheel speed sensor value VWFR, left front wheel speed sensor 2 left front wheel speed sensor value VWFL, right rear wheel speed sensor 3 right rear wheel speed sensor value VWRR, and left rear wheel speed sensor 4 Left rear wheel speed sensor value VWRL, lateral acceleration sensor value YG from lateral acceleration sensor 5, switch signal SWTC from TCS switch 6, switch signal SWST from brake lamp switch 7, throttle control module TCM (hereinafter, Throttle 1 actual opening DKV from TCM)
And the automatic transmission control unit A /
Gear position signal and shift-up signal from TC / U (hereinafter abbreviated as A / TC / U) and engine rotation from the engine centralized electronic control unit ECCS C / U (hereinafter abbreviated as ECCS C / U) The number signal and the second throttle signal TVO2 or the like from the second throttle sensor 17 are input.

Then, from the TCS / ABS-ECU, the acceleration slip is detected and the throttle 2 as a throttle opening / closing signal is detected.
The target opening DKR is output to TCM, and the solenoid signal as the brake pressure increase / decrease signal is output to each solenoid valve of the shared hydraulic unit TCS / ABS-HU (hereinafter abbreviated as TCS / ABS-HU). .. The throttle control side of this traction control is called TCS throttle control, and the brake control side is called TCS brake control.

The TCS / ABS-ECU detects a deceleration slip and outputs a solenoid signal as a brake pressure increasing / decreasing signal to each solenoid valve of the TCS / ABS-HU. This anti-skid brake control is called ABS brake control.

In addition to the above output, the TCS / ABS-ECU outputs a lighting command to the TCS fail lamp 14 when the TCS fails, and outputs a lighting command to the TCS operation lamp 15 while the TCS is operating.

The TCM is a control circuit centered on a throttle motor drive circuit, which receives the first throttle signal TVO1 from the first throttle sensor 16 and outputs it to the TCS / ABS-ECU as the throttle 1 actual opening DKV. Or input the second throttle signal TVO2 from the second throttle sensor 17 as feedback information for the throttle 2 target opening DKR, or input the throttle 2 target opening DK from the TCS / ABS-ECU.
A motor drive current IM is applied to the throttle motor 18 based on R.

Here, the first throttle valve 19 provided with the first throttle sensor 16 is the accelerator pedal 2
The second throttle valve 21, which is a valve that operates in conjunction with 0, is provided in the engine intake passage 22 in series with the first throttle valve 19 and is opened and closed by the throttle motor 18. It is a valve that is used.

As shown in the figure, the traction control system includes an air flow meter AFM as a peripheral system.
It has an ECCS C / U and an injector, and an engine centralized electronic control system that centrally controls fuel injection control, ignition timing control, idle speed correction, etc. is installed. When the ON signal is input, control for selecting a smaller valve opening of the first throttle signal TVO1 and the second throttle signal TVO2 (select low control) is performed to correct the transient characteristics, and the canister control and EGR control are performed. It will be canceled.

As the peripheral system, as shown in the figure, an A / TC / U and a shift solenoid are provided, and an automatic transmission control system for carrying out gear shift control, lock-up control, etc. is mounted. The gear position signal and shift-up signal are fetched from TCS / ABS-ECU.

Further, as a peripheral system, as shown in the figure, an ASCD actuator is provided, and a constant speed traveling control system for automatically controlling the vehicle speed so as to maintain the set vehicle speed is mounted, so as to prevent control interference, When the ON signal of the traction switch signal TCS SW is input, the opening control of the first throttle valve 19 is stopped, and when the OFF signal of the TCS SW is input, the return speed of the first throttle valve 19 is made gentle.

FIG. 3 is a hydraulic circuit diagram showing a brake fluid pressure control system commonly used for TCS brake control for the left and right rear wheels and ABS brake control for the four wheels.

This brake fluid pressure control system includes a brake pedal 27, a hydraulic booster 28, a master cylinder 30 having a reservoir 29, wheel cylinders 31, 32, and
33, 34 and shared hydraulic unit TCS / ABS-HU
(The configuration excluding both switching valves TV1 and TV2 is equivalent to the brake fluid pressure control actuator) and pump unit PU
, A first accumulator unit AU1, a second accumulator unit AU2 (corresponding to an external hydraulic pressure source), a front wheel side damping unit FDPU, and a rear wheel side damping unit RD.
It is equipped with PU.

The TCS / ABS-HU has a first switching valve TV1.
, Second switching valve TV2, left front wheel pressure increasing valve 36a
And right front wheel pressure increasing valve 36b and left rear wheel pressure increasing valve 36
c, right rear wheel pressure increasing valve 36d, left front wheel pressure reducing valve 3
7a, a right front wheel pressure reducing valve 37b, a left rear wheel pressure reducing valve 37c, a right rear wheel pressure reducing valve 37c, a front wheel side reservoir 38a, a rear wheel side reservoir 38b, and a front wheel side pump 39.
a, the rear wheel side pump 39b, and the front wheel side damper chamber 40a
And a rear wheel side damper chamber 40b and a pump motor 41.

During normal braking or ABS brake control, both switching valves TV1 and TV2 are turned off as shown in order to introduce the hydraulic pressure from the master cylinder 30.
When the TCS brake is controlled, both switching valves TV1 and TV2 are set to the ON position in order to introduce the hydraulic pressure from the second accumulator unit AU2. Then, for example, in the pressure increasing mode of the TCS brake control, both control valves 36c, 36d, 37c, 37d are as shown in the drawing.
In the OFF position and in the holding mode, the booster valve 36
Only c and 36d are set to the ON position, and in the depressurization mode, both control valves 36c, 36d, 37c and 37d are set to the ON position, the brake fluid from the wheel cylinders 33 and 34 is stored in the rear wheel side reservoir 38b, and further, By the rotation of the rear wheel side pump 39b, it is returned to the rear wheel side damper chamber 40b.

The first accumulator unit AU1 is used as a hydraulic pressure source for the hydraulic booster 28, and the second accumulator unit AU2 is used as a hydraulic pressure source for TCS brake control. Predetermined accumulator pressure is maintained by the common pump unit PU that draws in.

The front wheel side damping unit FDPU and the rear wheel side damping unit RDPU have a shared hydraulic unit TCS / AB in order to improve pedal feeling.
The influence of the change in hydraulic pressure on the S-HU is suppressed from affecting the master cylinder 30.

The operation will be described.

(A) Traction control action FIG. 4 is a control block diagram showing an outline of traction control performed by the TCS / ABS-ECU. The traction control logic can be roughly classified into the following four types of control.

(1) Calculation of Actual Slip State The signals of the wheel speed sensors 1, 2, 3, 4 are filtered, and the actual slip state (slip amount, slip amount difference value) is calculated based on the filtered wheel speed value. ) Is calculated.

(2) Calculation of target slip state The signal of the lateral acceleration sensor 5 is filtered to calculate a target slip state suitable for the running state based on the turning / straight ahead determination based on the lateral acceleration and the vehicle speed.

(3) TCS brake control Comparing the actual slip state and the target slip state, the required brake increase / decrease speed (control duty ratio) is calculated and output to TCS / ABS-HU.

(4) TCS Throttle Control Comparing the actual slip state and the target slip state, the necessary throttle opening and opening / closing speed are calculated and output to the TCM.

This control logic is characterized by low μ to high μ.
In order to secure the limit detectability (steering force, skill sound, etc.) based on the base chassis performance according to each road surface condition and to obtain active safety, the allowable slip state according to the magnitude of lateral acceleration, The allocation of throttle / brake control has been decided.

Further, in order to ensure stability during gear shifting and improve controllability at each gear position, throttle / brake control is performed according to the gear position.

Furthermore, in order to suppress slip hunting and realize a smooth acceleration feeling and controllability, and to realize a responsive engine torque increase / decrease control, optimum throttle control is performed according to the engine speed.

(B) ABS brake control action When the deceleration slip of each wheel exceeds the deceleration slip threshold value during braking, the solenoid signal as the brake pressure increasing / decreasing signal is independently applied to each wheel of each solenoid valve of TCS / ABS-HU. It is done by outputting to.

By this control, the wheel lock is suppressed when the braking force is likely to occur and the wheel lock is likely to occur, such as when the road is braked with a low coefficient of friction or during sudden braking.
The braking stability of the vehicle and the braking distance can be shortened.

(C) Normal brake recovery from TCS brake control FIG. 5 is a flow chart showing the flow of the brake recovery processing operation when the normal brake recovery is performed from the TCS brake control performed by the TCS / ABS-ECU. Each step will be described.

In step 50, it is judged whether or not the vehicle is in the acceleration slip state for executing the TCS brake control based on the calculation result of the actual slip state.

In step 51, the pressure reducing control time t ₂ (= K.multidot.K) according to the pressure increasing control time t ₁ in the TCS brake control.
t ₁ ) is determined (corresponding to the decompression time calculating means).

In step 52, it is judged whether or not the pressure reduction control time in the TCS brake control has exceeded the pressure reduction control time t ₂ obtained in step 51.

When NO is determined in step 52, the process proceeds to step 53, in which the shared hydraulic unit TCS / ABS-HU, which is the pressure control means, is set to the pressure increasing / holding / depressurizing mode according to the acceleration slip state. ..

If YES at step 52,
Proceeding to step 54, the second switching valve TV2 is turned on (communication) → OFF (shutoff), and 30 msec thereafter, the first switching valve TV1 is turned on (shutoff) → OFF (communication) and the pressure increase control valve 36c, 36d and the pressure reducing control valves 37c, 37d are turned ON → OFF to return to the normal state waiting for the brake operation (the steps 52 and 54 correspond to the first brake return control means).

When it is judged in the above step 50 that the TCS brake control is not controlled to the acceleration slip state, the routine proceeds to step 55, where the first switching valve TV
The first and second switching valves TV2 are kept OFF, and the pressure increasing control valves 36c and 36d and the pressure reducing control valve 37 are
c and 37d remain OFF.

FIG. 6 shows a time chart in the case where the normal brake recovery without the ABS brake control request or the like during the TCS brake control is performed according to the processing flow of FIG.

As described above, when the brake is returned from the TCS brake control, the second switching valve TV2 is first turned ON → OF.
F, and the first switching valve TV1 is turned on after a delay of 30 msec →
Since a time lag is provided in the switching timing so that the valve is turned off, both valves TV1 and TV2 momentarily become the communication side as in the prior art, and the second accumulator unit AU2
The hydraulic pressure from passes through the second switching valve TV2 and the first switching valve TV1 and escapes to the master cylinder 30, damaging the master cylinder 30, or both valves TV1, TV2.
Momentarily becomes the shut-off side, the hydraulic pressure of TCS / ABS-HU escapes to the wheel cylinders 33, 34, and the wheel cylinders 33, 3
It is possible to reliably prevent the occurrence of a feeling of deceleration by pressurizing 4 and putting the brake in an effective state.

Further, when the brake is returned from the acceleration slip control, the pressure reduction control time in the TCS brake control is obtained according to the pressure increase control time t ₁ as a switching timing for turning the second switching valve TV2 from ON to OFF. Since the pressure reduction control time t ₂ has elapsed, the brake is not restored while the high pressure brake fluid is being supplied to the wheel cylinders 33 and 34 due to the pressure increase in the TCS brake control, and then the acceleration slip is performed. When shifting to control or deceleration slip control, TC is used during pressure reduction control as in the conventional technology.
It is prevented that the brake fluid returned to the reservoir 38b of the S / ABS-HU exceeds the reservoir capacity limit and the pressure reduction control time cannot be set optimally, and the valve durability is not deteriorated.

(D) Brake recovery upon ABS request etc. during TCS brake control. FIG. 7 shows a case where brake recovery upon ABS request etc. during TCS brake control performed by TCS / ABS-ECU is performed. Each step will be described below with a flowchart showing the flow of the brake recovery processing operation.

Note that step 70, step 73, step 74, and step 75 are respectively step 5 in FIG.
There are steps corresponding to 0, step 53, step 54, and step 55, and a description thereof will be omitted.

In step 72, it is judged whether or not there is an acceleration request stop, an abnormality occurrence, and a deceleration slip request (ABS brake control request) (the steps 72 and 74 correspond to the second brake return control means). In addition, when the acceleration request is stopped, the accelerator opening becomes less than the set opening,
Output when brake operation is performed.

FIG. 8 shows a time chart when the brake recovery is performed according to the processing flow of FIG. 7 when the ABS brake control request (front 2ch) is issued during the TCS brake control.

As described above, even when the brake is restored in response to a predetermined request during the TCS brake control, the second
Since the switching valve TV2 is turned ON → OFF and the first switching valve TV1 is turned ON → OFF after a delay of 30 msec, a time lag is provided in the switching timing. It is surely prevented from occurring.

When the brake is restored from the acceleration slip control, the switching timing for turning the second switching valve TV2 from ON to OFF is set to the acceleration request stop, the abnormality occurrence, and the deceleration slip request output. Therefore, the TCS brake control side As in the case where the brake is restored after the predetermined depressurization time is secured, the increase in the braking distance and the feeling of delay in the braking response are prevented, and high responsiveness to these requirements can be secured.

The effect will be described.

(1) When the brake is returned from the TCS brake control, the second switching valve TV2 is first turned ON → OFF, and the first switching valve TV1 is turned ON → OF with a delay of 30 msec.
A time lag is provided in the switching timing so as to be set to F, and the pressure reducing control time in the TCS brake control is determined as the switching timing for turning the second switching valve TV2 from ON to OFF, which is determined according to the pressure increasing control time t _1. Since the control time t ₂ has elapsed, the master cylinder 30 and the wheel cylinders 3 are restored when the brake is returned from the TCS brake control.
It is possible to eliminate the influence of hydraulic pressure on 3, 34,
When the brake is restored in the normal state, it is possible to ensure proper decompression control thereafter.

(2) When the brake is returned from the TCS brake control, the second switching valve TV2 is first turned ON → OFF, and the first switching valve TV1 is turned ON → OF with a delay of 30 msec.
Since the switching timing has a time lag such as F, and the switching timing for turning the second switching valve TV2 from ON to OFF is the acceleration request stop, abnormality occurrence, and deceleration slip request output, the TCS brake control Master cylinder 30 and wheel cylinder 3 when brakes are restored
It is possible to eliminate the influence of hydraulic pressure on 3, 34,
When the acceleration request stop or the like occurs during the TCS brake control, high responsiveness to the request can be secured.

Although the embodiment has been described above with reference to the drawings, the specific structure is not limited to this embodiment.

For example, in the embodiment, the example of application to the traction control system by the throttle + brake is shown, but it can also be applied to the system which performs the traction control only by the TCS brake control.

[0069]

According to the first aspect of the present invention, in a vehicle traction control device having a brake fluid pressure control actuator shared during acceleration slip and deceleration slip, when the brake is restored from the acceleration slip control. , The switching timing of both switching valves is shifted, and the timing of switching the second switching valve to the shut-off side is the time when the pressure reducing time required to reduce the brake fluid pressure of the wheel cylinder to the predetermined pressure elapses. Since the control means is provided, it is possible to eliminate the influence of hydraulic pressure on the master cylinder and wheel cylinders when the brake is restored from the acceleration slip control, and when the brake is restored in the normal state,
The effect that it is possible to ensure appropriate decompression control thereafter is obtained.

According to a second aspect of the present invention, in a vehicle traction control device having a brake fluid pressure control actuator that is shared between acceleration slip and deceleration slip, both of when the brake is restored from the acceleration slip control Since the second brake return control means is provided for shifting the switching timing of the switching valve and for switching the second switching valve to the shut-off side when an acceleration request stop or the like occurs, the master is provided when the brake is restored from the acceleration slip control. It is possible to eliminate the influence of hydraulic pressure on the cylinders and the wheel cylinders, and it is possible to secure high responsiveness to the request when an acceleration request stop occurs during the acceleration slip control.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a vehicle traction control device of the present invention.

FIG. 2 is an overall view of a braking / driving system control system of a rear-wheel drive vehicle to which the vehicle traction control device of the embodiment is applied.

FIG. 3 is a hydraulic circuit diagram showing a brake fluid pressure control system of a braking / driving system control system to which the vehicle traction control device of the embodiment is applied.

FIG. 4 is a block diagram showing an outline of traction control in the embodiment.

FIG. 5 is a flowchart showing a flow of a brake restoration control processing operation when the brake is normally restored from the TCS brake control performed by the TCS & ABS electronic control unit of the embodiment apparatus.

FIG. 6 is a time chart showing changes in various signals when brake recovery is performed according to the processing flow shown in FIG.

FIG. 7 is a flowchart showing a flow of a brake restoration control processing operation when the brake is restored when there is an ABS request or the like during the TCS brake control performed by the TCS & ABS electronic control unit of the embodiment apparatus.

8 is a time chart showing each signal change in the case where an ABS request is made during the TCS brake control and the brake recovery is performed by the processing flow shown in FIG. 7.

[Explanation of symbols]

 a master cylinder b external hydraulic pressure source c wheel cylinder d brake hydraulic pressure control actuator e first switching valve f second switching valve g depressurization time calculation means h first brake restoration control means i second brake restoration control means

Claims (2)

[Claims] 1. A master cylinder that generates a hydraulic pressure by a brake operation, an external hydraulic pressure source provided separately from the master cylinder, and a brake fluid for a wheel cylinder that is shared during acceleration slip and deceleration slip. A brake fluid pressure control actuator for performing pressure control; a first switching valve for switching connection / disconnection between the master cylinder and the brake fluid pressure control actuator; disconnection / connection between the external fluid pressure source and the brake fluid pressure control actuator. During the acceleration slip control in which the second switching valve is switched and the first switching valve is the shut-off side and the second switching valve is the connection side, the brake fluid pressure of the wheel cylinder is changed according to the pressure increase time of the brake fluid pressure control actuator. Decompression time calculation means for calculating the decompression time required to reduce to a predetermined pressure, and acceleration slip control The second switching valve is switched to the shut-off side immediately after the pressure reduction time during control, and the first switching valve is switched to the communication side and the brake fluid pressure control actuator is returned to the normal state after a predetermined time from this valve shut-off. A traction control device for a vehicle, comprising: return control means. 2. A master cylinder that generates a hydraulic pressure by a brake operation, an external hydraulic pressure source provided separately from the master cylinder, and a brake fluid for a wheel cylinder that is shared during acceleration slip and deceleration slip. A brake fluid pressure control actuator for performing pressure control; a first switching valve for switching connection / disconnection between the master cylinder and the brake fluid pressure control actuator; disconnection / connection between the external fluid pressure source and the brake fluid pressure control actuator. A second switching valve for switching and a second switching valve immediately when an acceleration request stop or an abnormality or a deceleration slip control request occurs during acceleration slip control in which the first switching valve is on the shut-off side and the second switching valve is on the connection side. To the shut-off side, and after a predetermined time from this valve shut-off, switch the first switching valve to the communication side. The vehicle traction control apparatus for the second brake recovery control means for returning the Rutotomoni brake fluid pressure control actuator to the normal state, characterized in that comprises a.